Hello, I have a 1991 Honda Prelude Si. It has a DOHC and a 2.1L Engine. I have a few questions that I was hoping you all could answer. 1. I am looking at a Headers- Chikara Performance Steel Headers : JC Whitney: Auto Parts & Accessories First of all, how much will they help my car and secondly, They come in Ceramic Coated for $530 and Black Painted Steel for $240. The ceramic cost alot more but are they really worth it? Which would be better? 2.I am also looking at this exaust system for my car. Thermal POLISHED STAINLESS STEEL CAT-BACK PERFORMANCE SINGLE EXHAUST SYSTEMS : JC Whitney: Auto Parts & Accessories what do all of you think? would it be a nice chaice? Yes or no and why? 3.I am also Looking at this cold air intake Weapon-R SECRET WEAPON AIR INTAKE SYSTEMS : JC Whitney: Auto Parts & Accessories What do you all think of these parts? How much will they help my car? Thank you in advance for the help.